Hot line indicator useable with a plurality of hand tools



g 1957 A. L. RINIER ETAL 3,337,801

HOT LINE INDICATOR USEABLB WITH A PLURALITY OF HAND TOOLS Filed'March 6, 1964 INVENTORS. g 6 ALTON RZI a ATTORNEYS United States Patent Office 3,337,801 Patented Aug. 22, 1967 3,337,801 HOT LINE INDICATOR USEABLE WITH A PLURALITY OF HAND TOOLS Alton L. Rinier, 700 Peoples Merchants Trust Bldg.

44702, and James O. Zaiser, 2406 6th St. NW. 44708,

both of Canton, Ohio Filed Mar. 6, 1964, Ser. No. 349,903 4 Claims. (Cl. 324-133) This invention relates generally to small hand tools, and more particularly to an attachment to be used there with for the detection of voltages.

Heretofore, many accidents have occurred due to electricians or do-it-yourselfers coming in contact with voltages at unexpected points of their Work. The prior art teaches various tools for the sensing of voltages; however, all of the prior art tools have been of the type employing unitary construction, wherein the voltage detecting means are permanently afiixed thereto. Accordingly, it is possible to check for or detect a voltage at any particular time by the use of these special tools. However, if thereafter work is continued with a conventional hand tool it is possible for the user to come in contact with a high voltage and therefore be injured thereby because of his ignorance of the presence thereof. The only solution to this problem, outside of continuously checking for the presence of voltage by the use of the specially equipped hand tool, is to have a multiplicity of tools with voltage detecting and indicating means attached or specially made therefor.

Accordingly, it is an objectof this invention to provide a removably, attachable device which can be secured to any of a plurality of hand tools, such as, screw drivers, pliers, soldering iron, soldering gun, fuse puller, handles of electrical arc welding equipment, electric razors, etc.

It is another object of this invention to provide a voltage indicating attachment for use with a plurality of conventional hand tools which requires no individual power source.

It is another object of this invention to provide an attachment for use on conventional hand tools for the detection of voltages which is of safe and simple construction.

It is still another object of this invention to provide an attachment for conventional hand tools and thus enable a person to use ordinary hand tools in a voltage detecting system instead of having to purchase custom made and expensive voltage indicating devices or hand tools.

In accordance with the above and first briefly described, there is provide-d a universal testing device comprising an elongated sleeve or casing made of a resilient, non-conducting, compliant material. The material may have a high degree of transparency, or it may be of substantially opaque material. There is also provided a voltage indicating bulb which is embedded within the sleeve, along the outer surface thereof, for operator observation. The neon voltage indicating bulb is provided with two electrodes for receiving of electrical operating voltage thereto. One of said electrodes is positioned to extend through, and project out from, the inner surface of the resilient sleeve. Furthermore, current limiting means, totally embedded within the sleeve, are also provided. One of the terminals of the current limiting means is connected in circuit with the second electrode of the neon voltage indicating bulb. Circuit completing means fixedly positioned along the outer surface of the sleeve for user contact therewith are also provided. The heretofore unconnected terminal of the cur-rent limiting means is connected in series circuit arrangement with the circuit completing means. This sleeve will be capable of being removably mounted upon the current conducting handle of a conventional hand tool such that the inwardly projecting electrode of the neon bulb will make electrical contact with the current conducting tool. Furthermore, the operator will provide a complete circuit path for the series circuit arrangement including the handle of the hand tool, the projecting electrode of the bulb, the bulb the other electrode of the bulb, the current limiting means, the current completing means, the operators body and finally to ground. Accordingly, as the work tool contacts a voltage source current will flow therethrough from the projecting electrode to the neon bulb and the circuit will be completed by way of the current limiting means and the exposed circuit completing means contacting the operator to ignite the bulb and warn the operator of the eminent danger. Additionally, since the sleeve will be made of a resilient material having a yieldable centrally located, longitudinally extending chamber which will normally be of a lesser measurement than the outside diameter of the handle of the hand tool, it follows that the sleeve may be removed as the operator changes tools and placed upon the handle of his next choosen tool.

Further objects and features of the invention will become evident as details of construction and operation of the invention are explained in the ensuing specification, with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation view of my attachment shown removably mounted to the handle of a pair of pliers;

FIG. 2 is a central longitudinal section of my attachable sleeve showing the working relationship between the operational parts thereof;

FIG. 3 is a perspective view of my removably attachable sleeve with a broken away section along the outer surface thereof for illustration of the working relationship of the associated parts;

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 1;

FIG. 5 is a cross-sectional view taken on the line 5-5 of FIG. 3; and

FIG. 6 shows a second embodiment of my removably attachable sleeve being mounted upon a screw driver.

Referring to the drawings, there is shown in FIG. 1 a conventional pair of pliers having handles 12 and 13 pivotably connected by rivet 14, and having nose portions 15 and 16 with cutting edges 17 and 18. Removably attached to the handles 12 and 13 are insulating sleeves or casings 21 or 22. It should here be emphasized that the casings may be formed by any of the many Well known conventional molding means, for example, by injection molding. Furthermore, the steps whereby the various elements which are to be embedded within or along the outer surfaces of the casing or sleeve, may be carried out by means of a double die, injection molding procedure. Accordingly, we will pay short shrift to this particular phase of the formation of the device and merely let it be known that any of the conventional well known methods for forming these sleeves are within the scope of this invention.

Furthermore, it should be appreciated that the material from which the sleeves or casings are to be made are of non-electrical conductivity type and therefore provide a good insulation between the metal electrical conducting handles 12 and 13 of the hand tool and the operator thereof. Furthermore, the plastic material used can be of any type and have various characteristics; however, it is important that the material encasing the neon bulb have a high degree of transparency to enable the operator to see if it is conducting or not. Furthermore, in order for the sleeves to be compatible with various sizes of handles, it is important that the material have a high rate of resiliency.

Therefore, as is shown in FIGS. 1-3, a neon bulb is embedded Within the sleeve 21. The bulb 24, as shown in FIG. 1, could have been positioned along the outer surfaces of the handle by merely reversing the position of the sleeve relative to the handle; however, it was felt that if it were placed within the area enclosed by the two handles that it would be less susceptible to damage and breakage. Furthermore, the material encasing bulb 24 is of a high degree of transparency to permit optical communication thereof with the operator. Since the attachment will normally be applied to the handle of a hand tool, it follows that the attachment must have a shape and configuration generally corresponding thereto. Accordingly, as clearly shown in FIGS. 23, sleeve 21 is of elongated cylindrical shape having a cylindrical chamber or cavity 29 extending substantially throughout the length thereof. Sleeve 21 is shown being terminated in rounded end 31, however, it should be appreciated that it could as well have been left in an open ended condition.

Furthermore, in order to provide contact between an electrode of bulb 24, namely electrode 25, and the electrical conducting handle 13, it is important that electrode 25 be permitted to project through the inner surface of sleeve 21. FIG. 4 brings out the electrical contacting relationship between electrode 25 and handle 13. This is also brought out in greater detail in FIG. 2 whereat lead 25 is clearly shown to project a substantial distance into chamber 29 of sleeve 21. 'It should, of course, be appreciated that a metallic conducting tab or annulus could have been embedded along the inner surface of sleeve 21 with its outer surf-ace being generally flush therewith. Thereupon, electrode 25 would have made contact with the inner surface of the tab or annulus. Accordingly, contact between handle 13 and electrode 25 will be through the interposed tab or annulus in this latter case. Also, in order to limit the amount of current that flows through the bulb 24 upon the cutting edges 17 and 18, or noses 15 and 16 of hand tool 11 making contact with a high voltage, a current limiting means 28 is provided. As shown in FIG. 3, the current limiting means 28 may be a conventional resistor. However, it is within the scope of this invention that the current limiting means be a high resistance wire, a resistance formed by printed circuit techniques, or any of the well known means for limiting current.

One end of current limiting means 28 is connected in circuit with the second electrode 26 of neon glow bulb 24, see FIGS. 13. The other end of current limiting means 28 is shown to be connected in circuit with an annular electrical conducting ring 27. Annular ring 27 is shown in FIGS. 2 and to be embedded along the outer surface of sleeve 21 and having its outer surface flush with the outer surface of sleeve 21. As an alternate mode of construction, it is possible to have connecting lead 32, which provides the electrical contact between one terminal of current limiting means 28 and annular ring 27 exposed along the outer surface of sleeve 21 for operator contact therewith.

Accordingly, it can be seen that upon the operator making contact with a high voltage lead by way of cutting edges 17 and 18, or by the nose elements and 16 of the pliers, a current will flow through the handle 13 to lead of neon bulb 24. The operator being in gripping contact, by way of his hand, wtih the exposed surface of annular ring 27. Therefore, a complete current path is provided between the high voltage source and ground by way of handle 13, bulb 24, current limiting device 28, annular ring 27, and the body of the operator. It should be emphasized here that due to the current limiting capabilities of means 28 that the current flowing through the bulb is small and therefore the current cannot be felt by the operator and cause any harm to him, even though the voltage being detected and sensed may be of a high magnitude.

While we have shown sleeve 22 being used merely for purposes of insulating the current carrying handle 12 from the operator and user of the hand tool, it should be appreciated that it also could be equipped with a voltage detecting and indicating device as shown in sleeve 21.

FIG. 6 illustrates a second embodiment of my invention. As shown thereat, the novel co-operting elements of my invention are shown to be molded into an insulating handle 21 and thereafter the handle itself is fixedly attached to the shank 43 of screw driver blade 42. Bulb 24, electrodes 25 and 26, along with resistor 28 and circuit completing annular ring 27, co-operate in the same manner with shank 43 of the screw driver as sleeve 21 did with handle 13 of FIG. 1. Accordingly, as shown, electrode 25 is in electrical connecting relationship with shank 43 and ring 27 is shown to be connected to the electrode 26 of bulb 24 by way of current limiting device 28. Therefore, upon the operator making contact with a high voltage source electrical current will be transmitted by way of shank 43 to electrode 25. The bulb energizing circuit will then be completed through the body of the operator by his hand contacting the annular ring 27.

It should be appreciated that whereas FIG. 6 shows the handle 21 being molded to take on a usable handle form for the screw driver blade 42 that in screw drivers having electrical conducting metallic handles it is possible for the sleeve 21 of FIG. 2 to be slidably mounted thereupon in a manner similar to that which it assumes upon the handle 13 of pliers 11. Accordingly, in the latter case, electrode 25 will be making electrical contact with the metallic handle of the screw driver and it is unnecessary to have the sleeve premolded in the form shown in FIG. 6. Furthermore, even if the handle of the screw driver is of an insulating material, which is the usual situation, it is still possible that a sleeve having the form shown in FIGS. 2 and 3 can still be used therewith to perform the electrical testing function desired. In this case, what would be needed is that the elongated sleeve be of a sufiicient length so that it can be slidably mounted over the insulating handle of the screw driver in such a manner that electrode 25 will be making contact with the blade of the screw driver. It can be seen that if the elongated insulating sleeve 21 is made to override the entire insulating handle of a screw driver in such a manner that electrode 25 makes electrical contact with blade 42 that upon the operator making contact with an electrical source by the blade 42, a current will flow therethrough to electrode 25. From that point on the circuit will operate in the usual manner outlined above with the bulb energizing circuit path being completed by the gripping relationship of the operators hand around annular ring 27.

While we have limited this disclosure to two embodiments; namely, the pliers of FIG. 1 and the screw driver of FIG. 6, it should, of course, be appreciated that the sleeve can be slidably engaged with the handle or electrical conducting portion of many conventional, and commercially available hand tools. Therefore, it should be apparent that the embodiments of this invention herein disclosed are well calculated to fulfill the objects of the invention, and it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope of fair meaning of the subjoined claims.

We claim:

1. For use with any of a selected one of a plurality of commercially available hand tools having an electrically conductive working area, a voltage testing attachment comprising, an elongated sleeve made of a resilient, non-conducting, compliant material, said material having a high degree of transparency, a voltage indicating bulb embedded within the sleeve along the outer surface thereof, said bulb having two electrodes, one of said electrodes 7 being positioned to extend through and project out from the inner surface of the resilient sleeve for conductive contact with the conductive area of the tool to which applied, current limiting means totally embedded within u the sleeve, one terminal of said current limiting means being connected in circuit with the second of said electrodes of said bulb, and conductive means fixedly positioned along the outer surface of the sleeve for user contact therewith, the second terminal of said current limiting means being connected in circuit therewith.

2. For use with a selected one of a plurality of commercially available hand tools having an electrically conductive working portion, a voltage testing attachment comprising, an elongated sleeve of a resilient, non-conducting, compliant material, a voltage indicating bulb visibly embedded within the sleeve along the outer surface thereof, said bulb having two electrodes, one of said electrodes being positioned to extend through and project out from the inner surface of the resilient sleeve for conductive contact with the conductive portion of said tool, current limiting means totally embedded within the sleeve, one terminal of said current limiting means being connected in circuit with the second of said electrodes of said bulb, and circuit completing means fixedly positioned along the outer surface of the sleeve for user contact therewith, the second terminal of said current limiting means being connected in circuit therewith.

3. For slidable attachment with current conducting elements of a selected one of any of a plurality of commercially available hand tools having an electrically conductive area, a voltage testing attachment comprising, an elongated cylindrically shaped member made of a resilient, non-conducting, compliant material, a voltage indicating neon bulb embedded within the sleeve along the outer surface thereof, a protective highly transparent cover enclosing the bulb, said neon bulb having two electrodes, one of said electrodes being positioned to extend through and project out from the inner surface of the resilient sleeve to contact the conductive area of said tool, a resistor totally embedded within the sleeve, one terminal of said resistor being connected in circuit with the second of said electrodes of said bulb, and circuit completing means fixedly positioned along the outer surface of the sleeve for user contact therewith, the second terminal of said current limiting means being connected in circuit with said circuit completing means, such that upon said hand tool coming in contact With a voltage source said neon bulb will ignite to warn the operator.

4. For slidable attachment with current conducting elements of a selected one of any of a plurality of commercially available hand tools, a voltage testing attachment comprising, an elongated cylindrical shaped member made of a resilient non-conducting material, a voltage indicat ing neon bulb embedded within the sleeve adjacent the outer surface thereof and being visible externally of the sleeve, said neon bulb having two electrodes, one of said electrodes being positioned to extend through and project out from the inner surface of the resilient sleeve for contact with the current conducting elements of the selected tool, a resistor totally embedded within the sleeve, one terminal of said resistor being connected in circuit with the second of said electrodes of said bulb, and a metallic annular ring fixedly positioned along the outer surface of the sleeve for user contact therewith, the second terminal of said current limiting means being connected in circuit with said annular rign, such that upon a user of said hand tool coming in contact with a voltage source said neon bulb will ignite to warn said user thereof.

References Cited UNITED STATES PATENTS 1,638,438 8/ 1927 Gottschalk 3245 1 2,474,407 6/1949 Todd 324l33 2,476,115 7/ 1949 Runbaken 324-51 RUDOLPH V. ROLINEC, Primary Examiner. WALTER L. CARLSON, Examiner.

J. J. MULROONEY, Assistant Examiner. 

1. FOR USE WITH ANY OF A SELECTED ONE OF A PLURALITY OF COMMERCIALLY AVAILABLE HAND TOOLS HAVING AN ELECTRICALLY CONDUCTIVE WORKING AREA, A VOLTAGE TESTING ATTACHMENT COMPRISING, AN ELONGATED SLEEVE MADE OF A RESILIENT, NON-CONDUCTING, COMPLAINT MATERIAL, SAID MATERIAL HAVING A HIGH DEGREE OF TRANSPARENCY, A VOLTAGE INDICATING BULB EMBEDDED WITHIN THE SLEEVE ALONG THE OUTER SURFACE THEREOF, SAID BULB HAVING TWO ELECTRODES, ONE OF SAID ELECTRODES BEING POSITIONED TO EXTEND THROUGH AND PROJECT OUT FROM THE INNER SURFACE OF THE RESILIENT SLEEVE FOR CONDUCTIVE CONTACT WITH THE CONDUCTIVE AREA OF THE TOOL TO WHICH APPLIED, CURRENT LIMITING MEANS TOTALLY EMBEDDED WITHIN THE SLEEVE, ONE TERMINAL OF SAID CURRENT LIMITING MEANS BEING CONNECTED IN CIRCUIT WITH THE SECOND OF SAID ELECTRODES OF SAID BULB, AND CONDUCTIVE MEANS FIXEDLY POSITIONED ALONG THE OUTER SURFACE OF THE SLEEVE FOR USER CONTACT THEREWITH, THE SECOND TERMINAL OF SAID CURRENT LIMITING MEANS BEING CONNECTED IN CIRCUIT THEREWITH. 